The invention relates to an arrangement for the production of electroradiographic x-ray photographs according to the preamble of patent claim 1. Such arrangements are e.g. known from the U.S. Pat. No. 2,802,949.
Photoelectric exposure plates for x-ray images consist, as is known, of semiconductor layers which are applied onto an electrically conductive carrier. They are electrically charged and then exposed in a lightproof cassette to the influence of the radiation from which an image is to be formed. Finally, there remains on the surface of the photoconductive layer an electrostatic image. To avoid loss of image charge, an electrically insulating space is provided between the charged surface and the cassette lid. However, if this space is filled with air or another gas, an ionization is brought about during the irradiation which causes a reduction in the charge of the latent image at its edges on the photographic layer (ionization-induced undercutting). Moreover, due to the intermediate air space, a substantially thicker cassette is required than in the case of photofilms e.g. vacuum-packed "low-dose-systems".